Bacterial diseases, such as those caused by Neisseria gonorrhea and Staphylococcus aureus, pose significant disease and health risks. N. gonorrhoeae is the causative agent of the sexually transmitted disease gonorrhea (infection of the genitalia, and urinary tract) and cause of pelvic inflammatory disease and infertility in one million women a year. Worldwide, there are an estimated 62 million new cases a year, with an average of 22 million cases at any given time. About 0.8 million new gonorrhea infections are reported each year in the U.S. primarily among teenage females and African Americans, costing $1.1 billion/year in treatment and related expenses. Importantly, gonorrhea infections increase the transmission and susceptibility to human immunodeficiency virus infection. Moreover, gonorrhea has become resistant to traditional treatments with quinolone (ciprofloxacin), tetracycline, penicillin, and sulfonamides. Currently, twenty percent of reported gonorrhea cases in the U.S. and Europe are resistant to all of these drugs, with the highest resistance seen among homosexual males. Although gonorrhea can now be treated with ultra high doses of azithromycin, resistance to that antibiotic is also emerging.
The S. aureus bacterium currently causes the most common and serious infections that occur in hospitalized patients. In recent years, S. aureus has become resistant to antibiotics (thus named Multidrug- or Methicillin-Resistant S. aureus, MRSA), causing a serious public health problem in the United States and worldwide. Sixty percent of intensive-care-unit infections in the U.S. are caused by MRSA, leading to significant mortality. The MRSA “superbug” multiplies very rapidly in the bloodstream causing toxic shock syndrome, and/or on the skin causing furuncles. Once an infection occurs, it is almost impossible to treat with existing antibiotics, especially in immune-compromised and elderly patients. When an incurable MRSA infection reaches the heart, it often causes fatal endocarditis.
Hence, there is a growing need for alternative treatments against such bacterial pathogens.